Well, for a while now I've been under the impression that pullups were superior to pull downs for neuro physiological reasons. Pullups recruit more muscle fibers...more cns involvment etc.

I've been trying to find some details and sources for this...but came up empty. Some guys referred me to this site saying I'd find some. I also can't seem to get the stupid search function to work so sorry if you already have an article or something on it.

right, well... Free weight excercises are always better because they carry over to become functional strength.. when excercises on one plane of travel do not so much.. take the smith machine for example.. shunned by knowledgable lifters; it does not develop functional strength, or stabilizers.

Don't have any sources for you but the others can chime in about that im sure.

it's easy to find people who can do a lot of weight on pulldowns, but it's hard to find a brotha who can knock out 3x10 on pullups. and usually people that can do alot of pullups can still do decent weight on pulldowns, too...

He wants factual evidence aka studies something concrete to back up his claims. Search the archives here (4th link from the right at the top) and I believe you should find something.

Off the top of my head I would simply just show someone that they can't do as many pullups with their bodyweight as they can pulldowns. Which should let you know something fairly obvious... they're not the same.

A: The short answer? Because the biggest guys do them. The long answer? The pull-up forces you to train harder. Let's break it down.

The pull-up engages a greater number and higher threshold of motor units. This is due to the stabilizers firing to fixate the torso and keep it rigid and the relatively greater loads being placed on each muscle along the chain.

For example, it?s not uncommon to get serious DOMS (soreness) in the abs, glutes and hamstrings after eight sets of six reps of chins. With the pulldown, the lower and mid body is fixated by the machine and therefore those same muscles are inactive.

Additionally, many muscles along the chinning chain such as the abs, biceps, hamstrings and lower lat fibers are predominately fast twitch and respond best to the more intense effort that only the mighty pull-up can provide.

Let?s make one point clear. It?s only the "free," non-assisted pull-ups and chin-ups that are superior back developers. Assisted (machine) pull-ups are in many ways inferior to cable pulldowns. This is due to the potential for cheating on such devices. By flexing the hips, knees and or ankles on a pull-up machine, the trainee can create a significant plyometric effect. This leads to poor form and injury.

Stick to old fashioned pull-ups and chin-ups.

Now, although I don't gauge the effectiveness of a workout by the amount of soreness or DOMS I get, I do agree with Alessi.

Besides, as many Very Smart Buff Guys have said, the body functions as a unit in life and should be trained as one in workouts, at least most of the time.

Hopefully this answers your question. This was all I was able to find on the subject, but then it is almost 4am now, so I'm not really all here and only did a quick search. Do some reading on open-chain vs. closed-chain exercises for more thoughts.